IS : 7022 ( Part II ) - 1979 ( Reaffirmed 2003 ) Indian Standard GLOSSARY OF TERMS RELATING TO WATER, SEWAGE AND INDUSTRIAL EFFLUENTS PART II ( Second Reprint MAY ls)c>b ) UDC 628.1/.2:001.4 0 Copyright 1980 BUREAU OF INDIAN STANDARDS MANAK BHAVAN, 9 BAHADUR SHAH ZAFAR MARG NEW DELHI 110002 Gr6 May 1980 IS : 7022 ( Part Ii ) - 1979 Indian Standard GLOSSARY OF TERMS RELATING TO WATER, SEWAGE AND INDUSTRIAL EFFLUENTS PART II Water Sectional Chairman DR T. R. BEXASKARAN Members SIIRI N. S. B~IAII~AVAN Committee, CDC 26 Representing Geo-Miller & Co Pvt Ltd, Calcutta & Control Kerala State Board for the Prevention of Water Pollution, Trivandrum Test House, Calcutta Physical Laboratory SIIRI J. D: JOYSINOII ( Alternate ) National SHRI A. K. B~ATTACAAI~YYA Srtn~ K. D. DAS (Alternate) National Sa~r V. M. BiiUcu~~ SIIRI JITENDRA RAI ( Alternate ) CHIEF WATER ANALYST, KINQ INSTITUTE, MADRAS SHXI L. M. ClIOUDl1lZY Delhi ( CSIR ), New Director of Public Health, Government Nadu, Madras Haryana State Board for the Prevention of Water Pollution, Chandigarh of Tamil & Control SHRI M. L. PRABHAKAR (Akmate) SHRI S. K. CHA~~ABA~~YI Steel Authority of India Ltd, New Delhi SARI A. K. POUDAR ( Altrrnate I ) SARI A. K. DAS ( Alternate II ) Department of Environmental Hygiene (GovernSHRI A. DUI~AI RAJ ment of Tamil Nadu ), Madras The Fertilizer ( Planning & Development ) India SHRI B. K. DUTTA Ltd, Sindri SHRI G. S. RAY ( Alternate ) SHRI P. Garron~~ The ~l~;~tli~ Chemical Corporation of India Ltd, . a SHRI K. L. GHOSH SHRI P. K. CHAKRAVARTY (Alternate) DR M. I. GURBAXANI SERI MALLINATW JAIN SHRI K. R. Saau ( Alternate ) Rrgional Research Laboratory ( CSIR ), Bhubaneswar The Tata Iron & Steel Co Ltd, Jamshedpur Delhi Water Supply & Sewage Disposal taking, New Delhi Under2) ( Cortinwd on pap @ Copurigkt 1980 BUREAU OF INDIAN STANDARDS This publication is protected under the @&an Copright Act ( XIV of 1957 ) and reproduction in whole or in part by any meana except with written permission of the publisher shall be deemed to be an infringement of copyright under the said Act. IS17022(Partn_)-1979 ( Continuedfrom page 1) MdClS . .A; Refiresen ting ( CHEM ), RDSO, Railway Board ( Ministry of Railways ) JOL",'CIN~~~OR ASSISTANT CHEMIST&METALLURQIST. N. E. RLY, GORAKHmm ) ( jlltemate) Bhabha Atomic Research Centre, Bombay SHRI M. S. KRISHNAN Ion Exchange ( India ) Ltd, Bombay SHRI V. N. LAMBU SHRI M. S. BIDIKAR ( Alternate ) Bharat HeavvI Electricals Ltd. . Hvderabad SERI S. MAHADE~AN , SHRI S. B. KAPUR ( Alternntc I ) SHRI C. R. RANQANADHAN ( Alternate II ) All India Distillers' Association, New Delhi SHRI V. K. MALIK SITRI K. SURIYANARAYANAN (Alternate) Director of Industries, Government of Haryana SHRI K. MANIVANNAN Chandigarh Indian Chemical Manufacturers Association SHRI S. M. MXHTA Calcutta SHRI MAX~AL SINQX ( Alternate) West Bengal Prevention 8t Control of Water SIIRI S. K. MITRA Pollution Board, Calcutta hlunicipal Corporation of Greater Bombay MU~JICIP~L ANALYST M. P. State Prevention & Control of Water SHRI D. V. S. MURTHY Pollution Board, Bhopal MEMBER-SECRRTARY (Alternate) Central Food Technological Research Institute Dn V. SBEENIVASA MURTHY ( CSIR ), Mysore SHRI M. S. SIJBBA RAO I Alternate) Institution of Public Health Engineers. India SHRI S. K. NEOQI Calcutta DR M. BANERJEE ( Alternate ) National Environmental Engineering Researct SHRI R. PARAMASIVAM Institute ( CSIR ), Nagpur SBRI M. V. NANOTI (Alternate) Indian Institute of Science, Bangalore SHRt S. C. PILLAI The Fertiliser Association of India, New Delhi DR V. PAC~AIYAPPAN DR R. N. TR~VEDI ( Alternafe ) U. P. Water Pollution Prevention (cr Control San1 RAJ KUMAR Board, Lucknow SHRI V. P. GUPTA ( Al&mate ) Ministry of Works & Housing SHRI B. B. RAO Da I. RADHAKRIS~NAN (Alternate ) Karnataka State Board for Prevention & Control SHRI S. HANMANTH RAO of Water Pollution, Bangalore SRRI M. R. SETHUMADHAVA RAO ( Alternate ) Central Electricity Authority, New Delhi SHRI K. SREEDHARA RAO SHRI V. S. MURTI ( Alternate ) Central Board for the Prevention 8t Control of SHRI B. V. ROTKAR Water Pollution, New Delhi DR K. R. RAN~~ATHAN ( Alternate) ( Conliwd on page 24 ) 2 IS t 7022 ( Part II ) - 1979 ZndianStandard GLOSSARY OF TERMS RELATING TO WATER, SEWAGE AND INDUSTRIAL EFFLUENTS PART II 0. FOREWORD 0.1 This Indian Standard ( Part II ) was adopted by the Indian Standards Institution on 12 October 1979, after the draft finalized by the Water Sectional Committee had been approved by the Chemical Division Council. 0.2 Part I of the glossary covered terms used in relation to water, sewage and industrial effluents in the field of analysis and tests; industrial and domestic applications of water; treatment of water, sewage and industrial This waste; and disposal of sewage and industrial wastes after treatment. part covers terms relating to water supply and sewerage. 0.3 In the preparation of this standard, the following publications: assistance has been derived from A glossary of water and sewage terms used in sanitary engineering practice. Fifth European Seminar for Sanitary Engineers. World Health Organization 1956. Glossary - water and waste and waste water control engineering. 1969. American Public Health Association. American Society American Water Works Association. Water of Civil Engineers. Pollution Control Federation. I. SCOPE 1.1 This standard ( Part II ) defines terms widely used in relation to water suppIy and sewarage. 2. TERMINOLOGY A Absorbing Well - A shaft or well driven through an impermeable stratum to allow water to drain through to a permeable one. Also called drain well, negative well, dead well. 3 I8 : 7022 ( Part II ) - 1979 Absorption Loss - The loss of water, or the quantity of water lost, from a reservoir or canal by capillary action and percolation during the process of priming. After a canal or reservoir has reached a stable condition this loss is called seepage. Abyssinian - A well consisting of a perforated tube with a pointed end, driven into unconsolidated sediments, to tap shallow groundwater. Abyssinian Well - A tube with perforations above the pointed driven into starta of moderate hardness to obtain a supply of water. end, Activated Sludge Loading - The mass ( in kg ) of biochemical oxygen demand ( BOD ) in the applied liquid per unit volume of aeration capacity or per unit mass ( in kg ) activated sludge per day. Aerated Aerated Filter 1 A biological filter of special design in which the sewage or the filter medium is aerated. Pond - which mechanical supply * Aeration Period A natural or artificial waste water treatment pond in or diffused-air aeration is used to supplement the oxygen 1) The theoretical time, usually expressed in hours, during which mixed liquor is subjected to aeration in an aeration tank while It is equal to the undergoing activated sludge treatment. volume of the tank divided by the volumetric rate of flow of the waste water and return sludge, daily average volumetric rate of flow of the waste water and return sludge. time during which water is subjected to aeration. sewage is aerated. 2) Aeration The theoretical Tank - A tank in which Aerogines - One of the groups of bacteria included in the coliform group which, if present in preponderance, may indicate pollution of old origin or the result of growth such as that sometimes occurring in leather washers, jute packing, wood, etc. Aerobacter Aerobic Digestion - aeration. See digestion. Digestion of suspended organic matter by means of for the prevention of Afforestation Aftergrowth - The planting of trees, commonly soil erosion in catchment areas. - The regrowth to destroy it. treatment of vegetation, or bacteria in water after 4 IS : 7022 ( Part II ) - 1979 Afterprecipitation - The precipitation of colloidal calcium carbonate on the sand grains of a filter and/or in the pipe of the distribution system after treatment of the water with lime. Air Lift - A device for raising liquid by injecting air in and near the bottom of a riser pipe submerged in the liquid to be raised. Air-lift Pump - A pump, used largely for lifting water from wells, from which air under pressure is discharged into the water at the bottom of the well in fine bubbles. The bubbles mix with the water and reduce the apparent specific gravity of the air-water mixture, and the surrounding Also water causes the mixture to rise in the discharge pipe to the outlet. called air1 ift. Air Relief Valve - An air valve placed at the summit of a pipeline to release the air automatically and prevent the pipeline from becoming airbond with a resultant increase of pressure. Alfalfa Gate - In irrigation, a sheet-metal shear gate in a section of corrugated pipe, used for the control of water flow from sublaterals into fields and ditches. Algal Bloom - Large masses of microscopic and macroscopic such as green algae, occurring in bodies. of water. See Bloom. plant life Alkali Soil - A soil which has either so high a degree of alkalinity (pH B-5 or higher ), or so high a percentage of exchangeable sodium ( 15 percent or higher ), or both, that the growth of most crop plants is reduced. Alluvial Deposit reaches. Solid material deposited by a stream in its lower Alternating Double Filter filtration is carried out. Biological filter in which alternating double treatment of sewage by pairs of Alternating Double Filtration -The biological filters, the sewage passing through each unit of the pair in series; the order of passage through the filters is periodically changed. Anaerobic Contact Process - An anaerobic waste treatment process in which the microorganisms responsible for waste stabilization are removed from the treated effluent stream by sedimentation or other means and held in or returned to the process to enhance the rate of treatment. Anaerobic Digestion - The degradation about through the action of microorganisms oxygen. 5 of organic matter brought in the absence of elemental IS r 7022 ( Part II ) - 1979 Anaerobic Wqste Treatment - Waste stabilization brought about through the action of microorganisms in the absence of air or elemental oxygen. Usually refers to waste treatment by methane fermentation. Antichlors - Reagents, such as sulphur dioxide, sodium bisulphite, and sodium thiosulphate, which can be used to remove excess chlorine residuals from water or watery wastes by conversion to an inert salt. Anticorrosion Treatment - Treatment producing characteristics of the water. to reduce or eliminate corrosion Apron - An impervious cover ( for example of concrete ) at the top of a dam, sea wall, etc, to prevent turbulent erosion and/or hydrostatic uplift pressure. Artesian - Pertaining to groundwater, or things connected with groundwater ( for example a well or underground basin ), where the water is under pressure and will rise to a higher elevation if atiorded an opportunity to do so. Artesian Spring A spring issuing from a confined aquifer. Artesian Well -A well which withdraws water from an aquifer in which it is confined, under pressure, below an impermeable stratum. Artificial Rainfall - Water artificially applied in the form usually by a rainfall simulator for experimental purposes. Artificial Watercourse agencies. A surface watercourse constructed of rain, by human Aspirator - A hydraulic device which creates a negative pressure by forcing liquid through a restriction, thus increasing the velocity head. Used in the laboratory in place of a vacuum pump; sometimes used in place of sump pump. Can be used to aerate liquid. Assimilative Capacity - The capacity of a natural body of water to receive : (a) waste waters, without deleterious effects; (b) toxic materials, without damage to aquatic or human life who consume the water; and (c) BOD within prescribed dissolved oxygen limitc B Backflow The flow of a liquid in a direction reverse of that intended. Backshore - The part of the shore covered by water during exceptional storms only, especially those combined with exceptionally high water; the zone of the shore landward of the foreshore, acted upon by waves only during severe storms. 6 IS : 7022 ( Part II ) - 1979 Balancing Reservoir 1) A 2) holding basin in which variations in flow and coinposition a liquid are averaged. Also called equalizing basin. of A reservoir interposed in a water supply system at any point between source and consumer for the purpose of elasticity of operation to the distribution system. Valve controlled by the rise and fall of a floating ball. Screen with endless, moving band of screening medium. Screen consisting of bars, usually spaced 2.5 to 15 cm Ball Valve Band Screen Bar Screen apart. Basin 1) A natural or artificially created space or structure, surface or underground, which has a shape and character of confining material that enables it to hold water. The term is sometimes used for a receptacle midway in size between a reservoir and tank. Its water 2) A large slip or dock partially surrounded by quays. level is subject to fluctuations with the water level of the main body of water with which it connects. 3) The surface area within a given drainage system. 4) A small area in an irrigated field or plot surrounded by low earth ridges and designed to hold irrigation water. 5) An area upstream from a subsurface or surface obstruction to the flow of water. 6) A shallow tank or depression through which liquids may be passed or in which they are detained for treatment or storage. I Beach - The belt or zone along the shore, usually with a gentle slope toward the water, occupied by unconsolidated material, moving sand, or shore drift. The zone from the waterline to the place where there is a marked change in material or physiographic form, or to the line of permanent vegetation ( usually the effective limit of normal storm waves ). Bed 1) The bottom of a watercourse or any body of water. 2) A seam or deposit later in origin than the rock below, a regular member of the series of formations and not'an intrusion. Bed Load Sand, gravel, etc, carried by a stream along its bed. 7 IS t 7022 ( Part II ) - 1979 Benthal Deposit - Accumulation containing organic matter arising waste waters. on the bed of a watercourse of deposits from natural erosion or discharges of Bio-aeration - An early name for activated sludge treatment in which the air was introduced by surface diffusion and by slowly moving paddles. Biochemical Oxygen Demand ( BOD ), First Stage - The oxygen demand to stabilize the carbonaceous organic matter present in waste water. Generally, the test consists in measuring the oxygen depletion at 20°C for 10 days. Biochemical Oxygen Demand ( BOD ), Second Stage - The oxygen demand to stabilize the non-carbonaceous organic matter such as The test ammonia nitrogen, which is oxidized to nitrites and nitrates. consists in measuring the oxygen depletion at 20°C for the subsequent 10 days. The first stage and the second stage BOD is the total BOD for 20 days, expressed as ultimate BOD. Biodegradation ( Biodegradability ) - The destruction or mineralization of either natural or synthetic organic materials by the microorganisms bodies of water, or waste water treatment populating soils, natural Systems. Biological Filter, Trickling Filter, Percolating Filter, Sprinkling Filter, Bacteria Bed - A bed of coarse granular material, through which sewage or liquid wastes are allowed to trickle, and in which organic matter is stabilized by biological action. Biological Filtration - The process of passing a liquid through the medium of a biological filter, thus permitting contact with attached zoogleal films that adsorb and absorb fine suspended, colloidal, and dissolved solids and release end products of biochemical action. Biological Oxidation - The process presence of oxygen convert the organic into a more stable or a mineral fbrm. whereby microorganisms in the matter contained in waste water Biological Purification - The process whereby micl'oorganisms convert the organic matter contained in waste water into a more stable or a mineral form. Biological Treatment -- The treatment of water or removal of organic matter with the assistance of biological Bloom - Large masses of microscopic and as green algae, occurring in bodies of water. 8 macroscopic sewage for organisms. plant the life, such IS t 7022 ( Part If ) - 1979 Blow-Off Rooster Cock Pump or accumulations the water Booster The outlet on a pipeline deposited from the water. used in discharge water of - A pump installed on a pipeline on the discharge side of the pump. to raise the pressure Station - is used to increase pumps. Bore - A pumping station in a water distribution the pressure in the mains on the discharge system that side of the The tidal wave in a watercourse. A deep well of small diameter. Bore hole Break Point 1) In the chlorination point of water, containing ammonia at which the residual chlorine is a minimum. the point at which softening bed nitrogen, the 2) In water softening, its efficiency. Brook, Bulking Stream - starts losing A small watercourse. by the sludge of Sludge - of an excessive volume In activated sludge, the occupation so as to hinder efficient sedimentation. C Canal Capillary An artificial Fringe - watercourse Heights for navigation water or irrigation. rises by capillary action to which above the water-table. Balarice - Carbonate which neither nate hardness Catchment, Caulking Channel- The condition of equilibrium existing in a water deposits carbonate hardness nor dissolves the film of carboalready deposited. Area, Catchment Basin - Catchment The area drained by a watercourse or surface a joint water drain. by wedging under gravity, in a filling. usually open at the Making A conduit watertight liquid carrying top. Check Valve, Refiux Valve - does not permit Chloramine Valve which, when inserted fluid to flow back in the event of a burst. agents formed in a pipeline, of chlorine - A group of disinfecting on free or combined ammonia. by the action 9 IS:7922(PartII)-1979 Clear Well - Tank in which filtered water is stored at the treatment .plant. cock - A means of withdrawing liquid from a conduit or reservoir, regulated by a valve. Sometimes used for stopcock. of the number Colony Count, Plate Count - A determination bacterial colonies produced on a suitable solid medium. of Combined Waste water - A mixture of surface runoff and other waste water such as domestic or industrial waste water. Combined Sewer - A sewer intended to receive both waste water and storm or surface water. Confiaene Contact Bed - Place of meeting of two streams. A tank for the treatment of sewage, filled with a coarse The tank is filled and allowed to stand full, and then granular medium. emptied and allowed to stand empty. Contact Filter See Contact Bed. Contact Period - The time allowed for a disinfecting agent to act on the water under treatment before the water is fed to supply. Occasionally used also for any other reaction period, Contact Stabilization Process - A modification of the activated sludge process in which raw waste water is aerated with a high concentration of activated sludge for a short period, usually less than 60 minutes to obtain BOD removal by absorption. The solids are subsequently removed by sedimentation and transferred to a stabilization tank where aeration is continued further to oxidize and condition them before their reintroduction to the raw waste water flow. Critical Depth Critical Flow The depth at which the flow streaming non-turbulent to turbulent change from smooth to occurs, for a given discharge. Flow at critical velocity in an open channel. Velocity at critical depth. Critical Velocity Cross Connection could be contaminated or polluted. 2) A connection between a supervised potable water supply and an unsupervised supply of unknown potability. 1) A physical connection through which a supply of potable water 18 t 7022 ( iPartif ) - 1979 Crown - The inside top of the arch in a sewer, covered channel, conduit. Current Meter watercourse. An instrument or for measuring the velocity of ilow'in a D Dam -A structure, usually of earth, masonry or concrete, to prevent, or control the flow of a watercourse for navigation, waterimpound, supply, hydroelectric power, flood control, etc. Degradation water, The lowering of a river bottom by the action of flowing Degradation-Organic Matter - The oxidation and reduction of organic matter in stream and sewage.. Denitrihation -- Reduction action. of dissolved nitrates due to biochemical from a stream held in Deposit - A layer of solid matter formed by sedimentation of gas or liquid. Depomition- The process suspension in water. of subsidence of solid material Depresred Sewer - A section of sewer constructed lower' than adjacent sections to pass beneath a valley, watercourse, or other obstruction. It runs full or at pressure greater than atmospheric because its crown is depressed below the hydraulic grade line, Detention Tank - A tank used in water or `waste water treatment to provide adequate time for chemical or physical reactions to take place in the body of liquid being treate,d. Diffused Air Aeration - A method for supplying air to sewage in activated sludge treatment by blowing air into the sewage. Diffnaer Plate - A porous plate used in aeration tanks to dilIuse air or other gases in various water and waste water treatment processes. DifthrJer Tube - An air tube used in ,aeration tanks to diffuse air or other gases in various water and waste water treatment processes. Diffaaion Aerator - An aerator that blows air under low pressure through aubmerged porous plates, perforated pipes, or other devices so that small air bubbles rise through the water or waste water continuously. 11 IS t 7022 ( Part II ) - 1979 Digested Sludge - Sludge digested under either aerobic or anaerobic conditions until the volatile content has been reduced to the point at which the solids are relatively nonputrescible and inoffensive. Digestion Tank A tank in which digestion is placed is carried to permit out. digestion to occur. Digester - A tank in which sludge Also called sludge digestion tank. Dike An artificial watercourse usually for drainage. by discharge into water. to land purpose by of Dilution Disposal Direct spraying disposal The disposal of sewage of waste water Irrigation - Application through multiple outlet pipes, or furrows of waste water rather than raising crops. in which a perforated screening directly for the medium Disk Screen - Screen by a revolving disk. is carried water in which chlorine or other Disinfected Waste Water -Waste disinfecting agents.has been added, during or after treatment, to destroy pathogenic organisms. Ditch -- A small artificial watercourse for surface drainage. tank with a steep-sided sedimentation Dortmund Tank - Vertical-flow pyramidal bottom, mainly used for sewage. Dosing Siphon Siphon used for applying sewage to filters. rapid filters, or other of water in two stages : through Double Filtration - Filtration sand filters, without a coagulant, and then through slow sand whose capacity is thus increased. Drain - A conduit used waters. Drainage 1) In general, the removal of surface water Commonly by gravity or by pumping. and groundwater. for the carriage of storm water, or sewage from a given area either applied to surface water point or location with c drainage 2) The area from which water occurring at a given on a stream originates. In such cases, synonymous area ' arid ( watershed `. Dredge To remove deposits from under water. of a rotary Drilled Well - Well excavated by means which removes material by abrasion. 12 or percussion drill IS t 7022 ( Part II ) - 1939 Drilling Drinking Sinking a borehole by means Supply of a rotary or percussion drill. Water Supply - of water by driving fit for drinking. into the soil a well casing rainfall. medium is of Driven Well - Well constructed fitted with a suitable point. Drought Drum carried An extended period of dry weather or of deficient Screen - Screen in which a perforated screening on the circumference of a revolving cylindrical drum. Dry Weather Flow - The minimum flow in a watercourse in periods dry weather, or the normal flow in a combined sewer in dry periods. Dug Well - Shallow from drilled or driven Dunbar Filter medium is overlaid well excavated well. by hand which or power a tools as distinct coarse Biological filter in by a fine medium. E comparatively Eddy - A surface vortex. velocity in an eddy rather matter than the normal velocity and Eddy Current --The of a stream. Elutriation decantation. The removal of soluble mound from solids by washing for confining Embankment course, etc, within An artificial bounds. or bank a waterwater Evaporation - The loss of water or from the soil. as vapour from a body of surface of the conventional sludge process Extended Aeration - A modification which provides for aerobic sludge digestion within the aeration system, The concept envisages stabilization of organic matter under aerobic conditions and disposal of the end products into the air as gases and with the plant effluent as finely divided suspended matter and soluble matter. F Fermentation Fetch waves. The Tank distance A tank used to ferment over which wind can organic act on wastes. water to produce 13 18 : 7022 ( Part II j- 1979 Filter, High Rate - A trickling filter operated at a high average daily dosing rate, including any recirculation of effluent. The hydraulic loading is between 100 and 400 mldlhectare, and organic loading is between 0*4 and 2-O kg/ms. A trickling filter operated at a low average daily dosing rate. The hydraulic loading is between 10 and 40 mid/hectare, and organic loading is between 0.1 and 0*4 kg/m% The water lost as steam when a sample of hot boiler water is taken without adequate provision for cooling the sample. Float - Filter, Low Rate - Flash-Off - An appliance which rests in the surface of water or sewage, usually used for registering level or for operating a switch. Floating Cover - An airtight cover to a basin, which floats on the liquid in that basin or is supported by the pressure of gas cover that liquid. Flood 1) Inundation caused by excessive storm runoff. 2) The peak runoff in a watercourse following such rainfall. 3) Abnormal movement of the tidal wave towards the shore. Flowing Well Flume -A Foam - An artesian overflows'at the surface, well in which the water reaches and device in the form of an artificial transmission or .measurement of flow of water. open channel, for the The aggregate of minute bubbles formed in water (or other liquid ) by agitation, fermentation, aeration, etc. Foaming - In sewage treatment, surface tension. the production of foam due to reduced G Gravity Filter - A rapid sand filter of the open type, the operating level of which is placed near the hydraulic grade line of the influent and through which the water flows by gravity. Grease Trap - A basin, fitted with a scum-board, a liquid waste. Grit Washer - to remove grease from Device for removing organic matter from the grit settled from sewage. 14 18 : 7022 ( Part II ) -1979 Gronndwatet water-table Gutter artificial local lowering of the Lowering - The to enable work to be carried out in excavation in the dry. 1) A channel for collecting surface drainage from roads. 2) A channel for collecting surface drainage from roofs. 3) A channel placed above a rapid sand filter for collecting the wash-water. H Head - The pressure at a point defined in terms of the corresponding vertical column of liquid. Head Race - A channel supplying water to a water turbine. High WaterThe highest level reached by an incoming tide; frequently used also for the time of this occurrence. Horizontal-Plow Tank - usually longitudinally, Tank in which the liquid flows horizontally, or radially. House Sewer -- A pipe conveying Humus Sludge waste water from a single building to a common sewer or point of immediate disposal. 1) Sludge deposited in final or secondary trickling filters or contact beds. 2) Sludge resembling humus in appearance. Hypochlorination - settling tanks following Chlorination by calcium I hypochlorite or similar compounds. Impounding Reservoir - A reservoir built to impound the water from a catchment area and formed by damming the watercourse which drains that catchment. Infiltration - The movement of water through the surface into the soil or of water into an underwater conduit from the soil. Inflow - The water ( or sewage ) entering a basin, reservoir or treatment plant; often used as synonym for influent. I5 IS : 7022 ( Part II ) - $979 Intermittent Sand Filter - as the medium, Invert - An early type of biological filter, using sand and intermittently dosed with sewage to avoid clogging. The floor, bottom, or lowest portion of the internal cross section of a conduit. Used particularly with reference to aqueducts, sewers, tunnels and drains. J Jar Test - Laboratory scale test for effectiveness of coagulation and/or flocculation. L Laminar Flow, Streamline Flow - Flow in which the by the streamlines passage action frequently of of remain Leach parallel - to the axis of flow. mineral salts from the ground the shore To dissolve Drift - water. Littoral The material carried along by the tide; wind and waves. by an outgoing Low Water - The lowest level reached used also for the time of this occurrence. M Magnetite Filter - Filter for sewage, using magnetite oxide) as the medium, which can then be cleaned magnetite electromagnetically. Manhole Main - An access in a sewer provided a man to enter or leave the sewer. Sewer (magnetic by agitating iron the for the purpose of permitting 1) In large systems, the principal sewer to which branch sewers and submains are tributary; also called trunk sewer, In small systems, a sewer to which one or more branch sewers are tributary. 2) In plumbing, the sewer is connected. Marble Test - public sewer to which the house or building balance of A chemical test to determine the carbonate water. 16 IS : 7022 ( Part II ) - 1979 Marginal Chlorination -An obsolescent practice in which chlorination is carried out so as to provide a predetermined residual of chlorine after a rather short contact period, but without any determination of the nature of the residual. Mechanical Aeration activated sludge treatment A method of supplying by the mechanical agitation air to sewage of the sewage. in N Nonsettlable Matter - That nor float to the surface of water suspended in a period matter which of one hour. does not settle Nonsettlable Solids - Waste water matter that will stay in suspension for an extended period of time. Such period may be arbitrarily taken for testing purposes as one hour. 0 Oil Remover See Oil Separator. by flotation or other means, for the removal, Oil Separator - Equipment of oil from contaminated water. OutIet - The point of exit from a basin, conduit, stream of warer or sewage; frequently used also permitting such exit. reservoir, etc, of a for the equipment content and first Oxygen Balance - Difference between dissolved oxygen stage biochemical oxygen demand at a given point. Oxygen resulting Depletion - Loss of dissolved oxygen from biochemical or chemical action. P from water or wastewater Paddle Wheel - A water wheel with paddles or strips of wood or other Such a wheel may be constructed on material attached to its periphery. the side of a vessel or watercraft and revolved by machinery to move the vessel, or it may be set in a moving stream or under a full stream of water which causes it to revolve and generate water power. Percolation Petcock The movement of water through a permeable stratum. A small cock used for sampling. 17 IS : 3022 ( Part II) - 1979 Phytoplankton Pipeline other fluid. Plant plankton. made up of pipes, for carrying water, sewage or A conduit, Plain Setting Tank - A tank or basin in which water, wastewater, or other liquid containing settlable solids is retained for a sufficient time, and in which the velocity of flow is sufficiently low, to remove by gravity a part of the suspended matter. Plate Count - Number of colonies of bacteria grown on selected solid media at a given temperature and incubation period, usually expressed in number of bacteria per millilitre of sample. Plug Cock Cock with a valve The power closed by a cylindrical of a soft water or conical lead plug. from Plumb0 Solvency pipes and fittings. to dissolve Pondage - The holding back of water for later release, especially for water power. Also used for the water so held and for the storage available for such holding. Precipitation - The overall rain, snow and hail. deposit of meteorological water including Presumptive Coliform Count - A statistical estimate of the number of coliform in water detected under certain conditions of incubation ( medium, temperature, time ). Primary Filtration - The first stage of double Primary biological Sedimentation Basin treatment or filtration, R of rain falling in a given Rainfall - The quantity in units of depth ( for example mm per annum ). Raingauge -- An instrument Rake cleaning Equipment used of sand filters. for for the measurement clearing screens or time usually measured filtration. basin preceding A sedimentation of rainfall. for assisting in the Rapid Sand Filter--A filter for the purification of water, in which sand is used as the filter medium, and in which solids are removed mainly by mechanical action which may be assisted by a chemical floe. 18 IS : 7022 ( Part II ) - 1979 Rate of Flow - The volume of water flowing through a cross section of a conduit in a unit time. Recharging Regulating - an underground The addition, by natural or artificial aquifer. means, of water to Reservoir - A reservoir designed to enable the regime of the watercourse, upon which it is constructed, to be controlled, especially in times of flood and drought. Reservoir - A watertight structure for the collection or storage of water. Ridge and Furrow Tank - Aeration tank for activated sludge in which the bottom of the tank is a series of ridges .and furrows. Sprinkler -- A sewage sprinkler revolving on a centre spindle, frequently driven by the reaction of the discharged sewage. Rotary Runoff - The proportion of the rainfall of surface-water drain. S Saline Water -- which reaches the watercourse to 33 000 mg/l. Salinometer Water containing dissolved salts - usually from 10 000 the concentration of --A hydrometer dissolved salts in boiler water. Sand Trap -- A small basin used to determine for the removal of heavy inorganic solids from water. wastes Sanitary Sewer - A sewer that carries liquid and water-carried from residences, commercial buildings, industrial plants, and institutions, together with minor quantities of ground, storm, and surface waters that are not admitted intentionally. Scraper -- Equipment for the removal of-sludge, etc, from the sedimentation basins and after treatment installation. Scum Board - of scum. A baffle in the surface of sewage to prevent the passage Scum Chamber - In an Imhoff tank the chamber gas produced by the digestion passes. Seeding Material through which the has undergone Seiche - - A well-digested or ripened sludge that decomposition; used for seeding sludge-digestion tanks. Oscillation of the water in a lake. 19 IS : 7022 ( Part II ) - 1979 Sewage Fungus - water, containing A filamentous or gelatinous growth in heavily polluted colonial bacteria, true fungi and colonial protozoa. other than Sewer Appurtenances pipe or conduit, Sewer Arch Sewer Manhole - Structurks, devices, and appliances, that are integral parts of a sewer system. The curved top of a masonry sewer. access from the surface which wastewater or treatment 1 metre long into a sewer is of the ground Sewer Outfall - A shaft or chamber to a sewer. - providing through The outlet or structure finally plant discharged. The point of final discharge of wastewater effluent. Sewer Outlet Sewer Rod - A hard wood stick or light metal rod, nearly with a coupling on each end. Rods are joined and pushed to dislodge obstructions. Sewer System - Collectively, all of the property involved in the operation of a sewer utility. It includes land, waste water lines and appurtenances, pumping stations, treatment works, and general property. Occasionally referred to as a sewerage system. Silt - deposited Silting Suspended matter in water, generally of a size between clay and fine sand. of the Eapacity - The reduction of silt or other inorganic matter. Tank - inorganic or such matter or basin due to a of a reservoir of grease deposit Skimming Tank for the removal and oil by flotation and skimming. of water, in which sand is Slow Sand Filter - A filter for the treatment used as the filter medium, and in which mechanical removal of solids is assisted by biological action. Sludge Conditioning - Pretreatment of sludge to assist its drainage and filtration. Sludge Digestion Sludge Rising - Digestion lifting of sludge. of sewage sludge to the surface due to The entrained gases. and associated active sludge, Sludge Seeding - In biological treatment of waste water sludges, the inoculation of the unit process with biologically resulting in acceleration of the initial stage of the process. 20 IS t 7022 ( Part II ) - 1979 Sluice Gate channel. Device for controlling the flow of water in an open Sluice -- Gate for the control Sluice Valve Gate valve of water in an open channel. used in a pipeline. above the critical depth, hydraulic air is in Smooth Flow - Flow in an open channel, which an obstruction will produce backwater. Spillway -- Waterway structure for the passage in connection with of excess water. a dam or other tank for activated sludge in which Spiral Flow Tank -Aeration added in such a way as to promote spiral flow in the liquor. Spring Emergence Device of groundwater for scattering at the surface water at a defined location. Sprinkler Z%ZgZZ ( or sewage ) in drops. a straight edged blade of A scraping implement, similar material. usually Stabilization Lagoon - A shallow pond for storage of wastewater before discharge. Such lagoons may serve only to detain and equalize wastewater composition before regulated discharge to a stream, but often they are used for biological oxidation. See Stabilization Pond. Stabilization Pond - A type of oxidation pond in which hiological oxidation of organic matter is effected by natural or artificially accelerated transfer of oxygen to the water from air. Standard-Rate Filter - A type of trickling filter in which both hydraulic and organic loadings are relatively low, usually built to operate without recycling or recirculation of waste water. Static Head Stopcock The head corresponding to no discharge. A valve. Storm Sewer - A sewer that carries storm water and surface water, street wash and other wash waters, or drainage, but excludes domestic waste water and industrial wastes. Also called storm drain. Storm Water Surface of water small produced solids by heavy from water rainfall. ( or sewage ) by a in a Straining - Removal strainer or screen. Stratification - The formation body of water, due to differences of two more or less distinct of real or pseudo-density. 21 layers IS : 7022 ( Part II ) - 1979 stream Bank The natural confines of watercourse. Streaming Flow - Flow in an open channel, below the critical depth, in which an obstruction will produce a standing wave. Suction Head - That part of the effective head on a water turbine given by the vertical height between the turbine and the tail water. Surface Aeration liquid. The absorption of air through the surface of a Subsurface Irrigation - The application of water ( or sewage ) to the ground by means of perforated conduits buried in the ground. Swallow Hole - A point in a permeable course disappears into the formation. T Tailbay - The open chamber receiving turbine, drowned siphon, spillway, etc. Tail Water the discharge from a water formation, at which a water- The water below a water turbine, dam, etc. Tapered Aeration - Diffused-air aeration in which the amount of air introduced into the sewage is gradually reduced as the sewage passes from the inlet to the outlet. Taste Threshold - The taste which can just be detected observer when compared with taste-free water. by a sensitive in a body Thermocline -- The region of a rapid change of temperature of water showing temperature stratification. Time of Flow -- In storm-water drainage, the time taken for the storm water to flow in the sewer from the point of entry to the outfall or to the junction with. another sewer. Travel&g Sprinkler - A sewage sprinkler reciprocating biological filter, often driven mechanically by the sewage. Tributary augments it. A stream or river which flows into another across and the thereby Turbulent Flow to the axis of flow. Flow in which the streamlines do not remain parallel Two Stage Purification - The purification of sewage in two stages, for example first by activated sludge for aeration and second, nitrification by biological filters. 22 fS I 7022 ( Part II ) - 1979 V Vertical-Flow Tank - Tank in which the liquid flows upwards so that descending solids can assist flocculation. Viscosity - Resistance adjacent layers. of a liquid to relative sliding between two W exclusive of disinfection, intended Water Conditioning - Treatments, to produce a water free of taste, odour, and other undesirable qualities. Waterlogged Watershed Water-Table Saturated with water. area. Often used as a synonym for catchment The free surface of the zone of saturation. Weir -- An artificial obstruction with an horizontal lip used for measuring or controlling the level of a liquid. Well aquifer. A vertical shaft, dug or driven for abstracting water from an Well Casing - The metal, concrete or other material lining in a well. medium is Wing Screen - Screen in which a perforated carried on a series of rotating wings. Y Yield source. screening The amount of water that can safely be drawn from a particular 23 IS:7022 (PadI)( Co&xudfrom pagt 2 ) Representing Ltd, New Delhi of Commerce & Industry, Members Engineers India SHRI K. RUDRAPPA SHR~ S. N. CHA~RABA~TI ( Alfrrnatr ) Bom~ymb~~mber SHRI M. L. SHAH Tata chemicals Ltd, Bombay SERI R. M. SHAH SHRI R. K. GANDHI ( Altsrnatc ) Punjab State Board for the Prevention & Control SERI D. R. SINQAL of Water Pollution, Patiala SHIU QI~T RAI ( Afternafc ) Director of Health Services, Government of DR ( SHT) S. M. VACHEA Maharashtra, Bombay Director General, IS1 ( Ex-o$cio Mumbn 1 DR G. M. SAXENA, Director ( Chem ) &cretary SH~I N. K. SHARMA Deputy Director ( Chem ), IS1 Panel for Glossary of Terms Relating to Water, Sewage Industrial EfHuents, CDC 26 : P8 and Convener DR M. I. CURBAXANI Members National Environmental Engineering Research Institute ( CSIR ), Nagpur SHRI S. K. KESARWANI ( Alternate j' All India Institute of Hygiene & Public Health SHRI S. B. DE Calcutta Bhabha Atomic Research Centre, Bombay SRR~ M. S. KRIBENAN Ministry of Works & Housing SHBI T. K. VEDARAMAN SARI S. G. BHAT The Tata Iron & Steel Co Ltd, Jamshedpur 14 BUREAU Headquarters : OF INDIAN STANDARDS Manak Bhavan, 9 Bahadur Shah Zafar Marg. NEW DELHI 110002 Telephones Regional : 331 01 31 331 13 75 Offices : Telegrams (Common : Manaksansthe to all Offices) Telephone 331 01 31 ! 331 13 75 Central * Eastern Northern Southern t Western Branch : Manak Bhavan, 9. Bahadur Shah Zafar Marg. NEW DELHI 110002 : l/l4 C.I.T. Scheme VII M. V.I.P. Road, Maniktola. CALCUTTA 700054 : SC0 445-446, Sectbr 36-C. CHANDIGARH 160036 : C.I.T. Campus, IV Cross Road, MADRAS 600113 : Manakalaya. E9 MIDC. Marol. Andheri (East), BOMBAY 400093 Offices : 37 86 62 21843 41 29 16 6 32 92 95 `Pushpak', Nurmohamed Shaikh Marg, Khanpur, AHMADABAD 380001 t Peenva Industrial Area, 1 st Stage. Bangalore-Tamkur Road, BANGALORE 560058 Gangotri Complex, 5th Floor, Bhadbhada Road, T.T. Nagar. 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